D7 Form administration form

d7_admin_form.php

/**
 * Implements hook_form().
 * Admin form stripe configuration
 */
function mymodule_configuration_form($form, &$form_state) {

  $form['mymodule_mode'] = array(
    '#type' => 'select',
    '#title' => t('Mode'),
    '#options' => drupal_map_assoc(array('live','test')),
    '#required' => TRUE,
    '#default_value' => variable_get('mymodule_mode', ''),
  );

  $form['mymodule_live_pk'] = array(
    '#type' => 'textfield',
    '#title' => t('Live publishable key'),
    '#required' => TRUE,
    '#default_value' => variable_get('mymodule_live_pk', ''),
  );

  $form['mymodule_live_sk'] = array(
    '#type' => 'textfield',
    '#title' => t('Live secret key'),
    '#required' => TRUE,
    '#default_value' => variable_get('mymodule_live_sk', ''),
  );

  $form['mymodule_test_pk'] = array(
    '#type' => 'textfield',
    '#title' => t('Test publishable key'),
    '#required' => TRUE,
    '#default_value' => variable_get('mymodule_test_pk', ''),
  );

  $form['mymodule_test_sk'] = array(
    '#type' => 'textfield',
    '#title' => t('Test secret key'),
    '#required' => TRUE,
    '#default_value' => variable_get('mymodule_test_sk', ''),
  );

  return system_settings_form($form);
}